Scott Pecoriello


While the calendar clearly indicates the start of Spring, Old Man Winter isn’t ready to give up just yet. An unusually cold air mass combined with a strengthening low pressure system will lead to heavy snow and strong winds across the Plains and parts of the Midwest, and heavy icing further to the east. While April snowstorms aren’t unheard of, the scope of the region impacted by this storm as well as the magnitude, will make it rather rare.

Heavy snow, strong winds, and blizzard conditions are currently hitting the northern Plains hard, and will continue to do so through tonight and tomorrow as our storm slowly slides east. Right now blizzard warnings extend from North Dakota to Kansas with wind gusts over 50 mph at times and a foot or more of snow expected. While the Plains are taking the brunt of the system today, the Midwest will be under the gun tomorrow. Gusty winds between 25 and 45 mph along with 12-15 inches of snow will be possible from Minneapolis to Des Moines. The other concern that will grow as our storm progresses and continues moving east will be sleet and freezing rain. Iowa, Wisconsin and Michigan will be at highest risk for sleet and freezing rain, with several inches of Winter precipitation possible between Saturday night and Sunday.

At this same time between Saturday and Sunday, the leading edge of our storms precipitation will move into northern New England, especially Upstate New York and southern Canada. Snow will be less of a concern in these areas, as warmer temperatures aloft will allow for more sleet and freezing rain than snow. In fact, some guidance is beginning to print out a fairly significant amount of icing, especially for parts of northern New York State, Vermont and New Hampshire. The worst of this icing will begin Saturday afternoon and continue into Sunday afternoon.

Even areas further south into parts of southern New England will be at risk for some icing, which again, for April is very unprecedented. Northern Pennsylvania, southern New York, Interior Connecticut and Massachusetts will all have the chance for freezing rain and sleet on Sunday morning. The significant icing will likely remain further north and west.

Some snow will also be possible across the Northeast, but likely confined to extreme northern New York, Vermont, New Hampshire and Maine. Up to 4 inches can be expected by Sunday.

This will be a rather long duration event, with the actual storm system not moving out of the Northeast until Monday night. The heavy freezing rain and sleet will become all rain as the storm passes through on Monday, with some storms even possible further to the south. Once passing through, cold air will move in behind and some additional snow and rain showers will be possible on Tuesday.

The first part of our storm has been working on the northern Mid-Atlantic all day today, and will likely continue into the overnight hours with more sleet and snow from Pittsburgh to Washington DC to Philadelphia. Even New York City is on the edge of the snow now. Total accumulations from this first part will range from 2″ to 5″ along the I-95 part of it, and over half a foot as you head westbound into parts of Maryland and south-central Pennsylvania. We wish we could tell you that after this moves through it’s all done, but unfortunately that’s when things are really just going to get started.

The second part of our storm (the main event) is already gaining steam over parts of the eastern Midwest states, and will continue to do so overnight and into the morning. As it does so precipitation will rapidly expand over Virginia, Maryland and parts of Pennsylvania, and soon after the east coast of the Mid-Atlantic. This rapid expansion will allow heavy snow to break out for millions across both parts of the country, and won’t be in much of a hurry to leave. Starting early tomorrow morning we anticipate moderate to heavy snow to be flying from the majority of Pennsylvania down through West Virginia, Maryland, Virginia, and then over into New Jersey, Southern New York and Connecticut. While the coast will struggle to see snow at first (eastern suburbs of Washington DC, the Delmarva, and southern New Jersey) as our storm rotates offshore, very cold air for this time of the year will seep southward and allow for a full transition. This should happen during the early and late afternoon as our storm begins to peak.

It’s around this time that the major I-95 cities from Washington DC to New York City will see the brunt of the storm, with bands of snow containing very heavy rates (between 1 and 3 inches per hour at times), gusty winds, and even some thundersnow as well. It’s likely that as we head into the evening and nighttime hours we see a deformation band of snow setup from Philadelphia to New York City and even into parts of southern New England. Our most recent data is suggesting that whoever gets stuck under this band will likely be in the sweet-spot for this storm, with as much as 6-12″+ accumulating.

Our updated snowfall map above (which is our final call) shows the swath of 6-12 inches extending all the way from south-central Pennsylvania and northern Maryland into southeastern Pennsylvania, central New Jersey, and extreme southern New York state. To the north of this swath there will be a very tight gradient for snowfall. All day we’ve been trying to figure out where exactly this will setup, and now we believe it will be across central Pennsylvania, extreme northern New Jersey and southern New England. That means that areas just 10-20 miles apart may see the difference between a foot of snow and just a few wet inches. Unfortunately the preciseness of which town sees what won’t be nailed down until during the actual event.

Wind is also a growing concern as we expect gusts that are currently developing to become even stronger and move northbound overnight. Places along the coastline from southern New Jersey to Boston will see the worst of the winds, with gusts between 45 and 60 mph possible during the peak of the storm.

Even outside of that region gusts above 35 mph will be possible from the Appalachian mountains through a large part of Pennsylvania and into New England. The only piece of good news with this is that the timing of the strongest winds and heaviest snows seem to be off from each other, so they are likely to only overlap for a shorter period.

Still, the combination of heavy wet snowfall, strong gusty winds, saturated grounds and weakened trees from previous storms will lead to additional significant problems. A large portion of both the Mid-Atlantic and Northeast will likely deal with power issues and tree damage. This will make travel extremely difficult to impossible for most of tomorrow, and could leave people without power for days. We do NOT advise traveling tomorrow, especially for areas who are forecasted to receive more than 6 inches of snow and wind gusts above 35 mph. Conditions will be dangerous.

The entire corridor from Pittsburgh to the Appalachians to Washington DC and the major I-95 corridor through Boston will be at risk for widespread power outages. While that doesn’t mean that your are guaranteed to lose power, it does mean that there is a rather high chance and that many homes and business around you will go dark at some point.

Even areas back towards the Midwestern states and up into New England could see power issues due to the nature of the heavy wet snow as well as the weakened trees from the past three systems that have moved by.

Our storm will finally begin to collapse and pull away from the region by Thursday morning, but again, it won’t be a fast mover. Even into the very early morning hours of Thursday these I-95 cities could still be seeing flakes. New England may even see flakes well into the afternoon and evening on Thursday, and parts of northern Maine could see snow showers into the overnight hours.

Our thoughts are that by mid-morning and afternoon on Thursday though, cleanup efforts can begin. And for those wondering if this is the last in this insane series of major storms.. We sure hope so. More updates tomorrow.

As Spring begins and we look forward to warmer temperatures and longer days, we’ll be dealing with quite the opposite over the next 48 hours. Yet another powerful coastal storm is developing this morning and will bring more heavy snow, gusty winds, and ice to both the Mid-Atlantic and Northeast. While this will be another nor’easter / coastal system, it won’t be like the last three we dealt with this March. Instead it will come in two separate rounds as a series of low pressures develop along and off the Mid-Atlantic coastline.

The first round is currently underway, and will be the icy part of our storm. As we move through the day, a mixture of heavy sleet, freezing rain, snow and rain will move through the northern Mid-Atlantic cities like Washington DC, Baltimore and Philadelphia. This will create a mess for the afternoon and evening commutes with up to a quarter inch of ice and sleet falling in some places. As wind gusts increase and ice accumulates on some power lines and trees, more damage like we saw with the last two storm systems will be possible. This means a large area of scattered to widespread power outages as well as trees and branches falling.

Power outages and damaged trees will be the greatest threat to the corridor extending from extreme eastern West Virginia and southern Pennsylvania to the northern suburbs of Washington DC, and then through Baltimore and up into Philadelphia, New York City and southern New England. These are the areas that will see the worst of our storm system with heavy snow, icing, and gusty winds.

As this first piece of our storm slows down, a second, more powerful piece will develop offshore. Colder air will be in place from the first system allowing northern air to infiltrate the entire region down to the coastline, and force most mixed precipitation to changeover to all snow. Our newly formed low pressure will then track in a northeasterly fashion, and spread moderate to heavy snow all the way from central Virginia to central Pennsylvania and out east into southern New England.

The most difficult aspect of this forecast right now is how close the low come to the coast and how far back the precipitation field extends. Computer model guidance has been waffling back and fourth on where to place the cutoff and heaviest snow, but at this point it seems like a safe bet to say the I-95 corridor from Baltimore to New York City will be in the best (or worst depending on how you feel about snow) spot. Beginning Wednesday morning and lasting through the evening, bands of heavy snow and gusty winds will move through this region, while also branching out to the north and west through much of south-central Pennsylvania and southern New England.

Our latest forecast calls for a very widespread area of 6+ inches of snowfall extending from around Pittsburgh through Philadelphia and into southern New England. This region will see localized totals of up to a foot of heavy wet snow. There will also be a small swath with over a foot of snow will be possible, extending from the suburbs just north of Philadelphia to central Long Island to Rhode Island. With winds increasing during the day on Wednesday and the worst of the snow falling around that time as well, conditions will be hazardous for traveling.

Our storm wraps up Wednesday night and Thursday before sunrise, with temperatures rebounding nicely during the day. The good news is the snow that does fall shouldn’t stick around for too long. What we really have to focus on at this point though before we reach the end of our storm, is where the placement of heaviest snow and our tight cutoff set up. Again, for now we believe that the I-95 corridor and suburbs to the north and west will be in the sweet spot for snow, but shifts are still very much possible. If new data from the NAM and ECMWF gain more support today, we will likely shift this swath slightly to the south and east, taking a good portion of southern New England out of the brunt of the storm, and seeing areas like the Delmarva moving into the thick of things. Another update this evening will have that covered.